Lalande Type Battery

One of the great inconveniences of radio apparatus using audion bulbs is
the excessive cost of the storage batteries used for igniting the
filament, so use of bulbs not knowing any substitute for the storage
batteries.

We have therefore thought it well to make known this battery, of slight
cost, which can replace the ordinary storage battery.

The battery described is neither more nor less than the well known
Lalande or oxide of copper battery, whose most notable properties are: Not consuming its zinc
and depolarizer except in proportion to the work which it does; long
duration; and large electric capacity.

One of these elements which we are going to describe, can supply a
one-bulb apparatus for a period of approximately 100 to 110 hours. Fig. 1
shows the small model whose approximate data are the following:

Normal constant current, one ampere,
which may be increased temporarily to 2 or 3 amperes.

The anode of the cell of this battery consists of
a cylindrical box of sheet iron, which for the upper 2 inches of its 4 1/2 inches of height,
is perforated with holes; the interior is filled with black copper
oxide; the whole then wrapped with
porous cloth, introducing only inappreciable resistance.

The cathode is a zinc plate 5 1/4 inches wide, 3 1/2 inches high, and about
3/8 inch thick. Anode and cathode are hung from the edge of the jar, which may be
made of glass. The large model shown in Fig. 2 gives the following characteristics:

The construction of this model differs
from the one just described only in the cathode, which is now a
cylinder surrounding the anode and held concentric therewith by glass or porcelain separators.
The dimensions
are: Anode, 2 3/4 inches high by 11 1/4 inches wide. Cathode 4 1/2 inches high by 8 1/2
inches wide, and 1/25 inch thickness.

The solution is made with caustic potash dissolved in distilled water. The solution after cooling is poured
in until the electrodes are covered by one-half inch or one inch of the
fluid.

By the figures our readers will see the
most convenient form to select for the electrodes. A battery of four such
elements each one of an electromotive force of .8 to .9 volts, can supply
the filament of a French bulb for 110 hours.